Composite shaped articles such as bathtubs, bathtub and shower enclosures, shower stalls, basins, and the like comprised of synthetic resinous materials are known and have become increasingly popular due, inter alia, to their light weight, ease of installation, and easy maintenance. One such type of resinous shaped article is comprised of a relatively thin gel top coat comprised of thermoset polyester, a supporting layer underneath said top coat comprised of a chopped glass fiber filled or reinforced thermoset polyester, an intermediate layer underneath said supporting layer comprised of polyurethane foam containing no reinforcing fibers, and a bottom layer underneath said intermediate layer comprised of chopped glass fiber reinforced thermoset polyester.
While such resinous composite shaped articles are very useful and satisfactory, they suffer from one drawback. This drawback is present in the manufacturing process used to produce said article. This composite article is made by first depositing the gel top coat layer on the outer surface of a mold, then depositing the supporting layer onto the gel coat layer, followed by depositing the intermediate layer on the supporting layer, and finally depositing the bottom layer on the intermediate layer. Since the gel top coat layer is quite thin and thus susceptible to puncture, deformation, and other damage, the supporting layer must be free of voids, air-pockets, and the like. However, the fiber glass filled thermosettable polyester supporting layer, as deposited by spraying, generally is not sufficiently free of such voids, air-pockets, and the like. These imperfections must be removed from the polyester resin before the thermosettable polyester resin is cured or thermoset. This may be accomplished by passing a roller over the glass filled thermosettable polyester deposit to remove any voids, airholes, and the like present therein. However, this is a rather time consuming and labor intensive procedure, particularly if the composite article is of a complex shape or form.
Furthermore, it would be advantageous if such a composite article were provided which exhibited a similar strength and rigidity while being lighter in weight.
The present invention provides a composite article wherein the rolling step in the preparation of the supporting layer is eliminated, and provides a composite article having substantially similar strength and rigidity but being lighter in weight.